Motor-controller.



N0- 809A60. PATENTED JAN. 9. 1906. A. PEDERSEN.

MOTOR CONTROLLER.

APPLICATION FILED MAY 26.1905.

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g rdfiulw M No. 809,460. PATBNTEDJAN. 9, 1906. A. PEDERSEN.

MOTOR. CONTROLLER. APPLICATION FILED MAY 26.1905.

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g 5 r F ,2 j ///1 AV/ 3 6" PATENTED JAN. 9, 1906.

A. PEDERSEN. MOTUR CONTROLLER. APPLICATION FILED MAY 26.1905.

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3M mm] l i I UNITED STATES PATENT OFFICE.

ADOLPH PEDERSEN, OF CLEVELAND, OHIO, ASSIGNOR- TO THE VAN DORN- ELLIOTT ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

.MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented Jan. 9, 1906.

To all whom, it may concern;

Be it known that I, ADOLPH PEDERSEN, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Motor-Controllers, of which the following is a specification, the principle of the invention being herein explained and the best mode in whichIhave contemplated applying that principle, so as to distinguish it from other inventions.

My invention relates to controlling mechanism, and especially to such mechanism as is adapted to control the motors used in electrically operated portable drills and other electrically-driven tools and machines.

-. Said invention consists of means hereinafter fully described, and specifically set forth in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure 1 represents a vertical axial section of my improved controlling mechanism in combination with a suitable casing for a portable drill and a motor supported therein. Fig. 2 represents a horizontal section of such controlling mechism, taken upon the planes indicated by the lines 2 2, Fig. 1. Fig. 3 represents a vertical section taken upon the plane indicated by the line 3 3, Figs. 1 and 2. Fig. 4 represents a vertical section taken upon the planes indicated by the lines 4 4, Fig. 2 and Fig. 5 is a diagram illustrating the circuit connections.

My invention relates to the controlling apparatus of an electrically-driven tool or machine, and I have illustrated said invention in one of its uses as particularly applied to a portable electrically-operated drill, such as is described and claimed in my prior application for United States Letters Patent upon electrically operated portable drills, Serial No. 224,953, filed September 19, 1904.

As shown in the above-mentioned application, I provide a suitable casing A for the 5o drill and connected mechanism, such casing having an intermediate diaphragmA extending transversely across the same and an upper removable head or cap A and a lateral removable portion A within which is inclosed the controlling mechanism forming the subject-matter of this invention. W'ithin the casing A and suitably secured thereto are the four pole-pieces E of a field structure surrounding the armature E of a multipolar series wound constant potential electric motor, suitably secured to a motor shaft. (Not shown.) The upper removable head A is provided with a central aperture a, having a screw-thread, and the diaphragm A has a central aperture a in alinement with the aperture a, and through said apertures the spindle of the drill and the feed-screw therefor are adapted to be inserted, as explained in my above-mentioned prior application. \Vithin the diaphragm A are suitable bearings (L in which are journaled pintles, that carry upon their lower ends two pinions adapted to mesh with a gear wheel (not shown) keyed upon the drill-spindle, and upon their upper ends two pinions adapted to mesh with a gear wheel (not shown) keyed upon the motor-shaft, all as is clearly shown and described in said prior application.

The electrical drills that are at present in use are not adapted to general application, in so far as I am aware, and the reason for this is as follows: It is usually desired that very rapid work be performed, and in order to accomplish this the drill must be forced to its work by some suitable manually-operated screw device. If the turning of the said feedscrew is effected by an inexperienced man, the normal proper speed of the motor is ac celerated or retarded, and if the speed becomes too slow, such as when the drill is just breaking through the work, the armature not being able to revolve the drill will suddenly stop, and if the drill is not provided with fuses the machine will be immediately burned out. If the drill is provided with an ordinary circuit breaker, the machine will not always be protected, for the operator soon discovers that he can defeat the object of the circuit-breaker and prevent it from operating by simply holding it down, thus causing the drill to do more work. I have sought to eliminate this trouble and provide a drill which is at all times reliable and proof against the carelessness or ignorance of an inexperienced man by providing the automatic controlling mechanism, which will now The machine being be described in detail.

series-wound and series-connected, the magnetizing force will rise with the current, and

by placing a small solenoid directly on the back of the fieldcore and connecting the same accumulative with the field-windings I am enabled to break the current at any time that the magnetic flux of the motor has reached a predetermined quantity. Of course no action would result if the solenoid were placed elsewhere and connected so as to oppose the field-windings to which it is connected.

A handle for the drill is illustrated at B, provided with a suitable outer screw-thread and adapted to be connected to an inter nally-screw-threaded integral projection a upon the lateral portion A of the casing. An operating-sleeve C surrounds the lower portion of the handle B and is rotatably secured by means of ascrewcto the stem (1 of an insulating semicircular switch-disk D, as plainly shown in Figs. 1 and 4, a suitable slot 01 Fig. 4, being provided in the handle B through which the screw 0 may travel when the operating-sleeve O isactuated, thus making the handle B non-rotatable. By thus making the handle B immovable and also of quite a length and removing its outer end some distance from the operating-sleeve C the drill can be carried or rolled about by means of said handle and another handle (not shown) connected with the other side of the casing without any danger of accidentally revolving or disturbing the operating-sleeve C.

As plainly shown in Fig. 1, a solenoid H is secured upon the core of one of the field-poles E by means of a screw G, formed out of a magnetic material which is locatedwithin and under the influence of the magnetic field and assists the solenoid in pulling a screw F inwardly, which screw F serves as a cut-out magnet and forms the core of the solenoid and is adapted to be actuated when the magnetic flux of the motor has reached apredetermined quantity, such quantity being varied as is desired, since the cut-out magnetF is adjustable by being screwed through a suspension-ring], as plainly shown in Figs 1, 4, and 5. Pivoted to this suspension ring f by means of pins j is a forked magnet and switch-lever J, provided at its outer end with a shoulder j, engaging with a pin Z when the cut-out magnet F is in its normal upward position, which pin l -is secured in an element J, pivoted in ears 1' projected upwardly from an insulated base N supported upon the casing A. The lever J is pivoted in uprights K, also projected upwardly from the insulated base 1 A spring Z tends to turn the element J upon its pivot 1 but is normally prevented from so doing by the engagement of the pin Z with the shoulder j, as plainly shown in Fig. 5. A second spring Z serves to assist the weight of the lever J in holding the shoulder j to engagement with the pin Z The spring Z is a wound-wire spring and is adapted to throw out a knifeswitch L, and thus break the circuit between the switch-poles L, as plainly shown in Fig. 5, when'the cutout magnet F is drawn withinthe solenoid H and the shoulder y" thus freed from the pin Z In Figs. 1 and 2 the insulating switch-disk D is shown in its full on position. Said switch-disk D is provided with a projection (1 forming a cam-face, as clearly shown in Figs. 1, 2, 3, and 4, and when the operating-sleeve C is actuated to turn the switch-disk D to its off position, which would be in the direction of the arrow, Fig. 2, said cam-face d contacts with the element J to move the same back to its normal upright position, as

shown in Fig. 5, and the pin Z again engages I with the shoulder j, so as to hold said ele- The circuit is illustrated ment J upright. at M, Fig. 5, and within such circuit is introduced a shunt N, having a resistance N, which shunt is rendered effective as follows: Secured to the under surface of the switchdisk D is a circular short-circuiting switch N supported upon a plurality of contact-clips n, which in turn are secured to supports n upon the insulated base N. When the switch-disk D is in its full off position, the circuit is of course broken and is not again made until the switch-disk has been revolved sufficiently toward its full on position to bring the short-circuiting switch N upon the two left hand contact clips n, Fig. 5, which passes the current through the shunt N until the forward end of the switch N" contacts with the right-hand clip n, thus passing the full current through the circuit. By thus introducing the shunt into the circuit 1 obviate the danger which is present when the full current is turned on all at once. A suitable reversing-switch O is provided, having an operating-handle 0, adapted to be interlocked with the operating-sleeve C, said handle 0 being operative only when the sleeve C has been turned to hold the disk D in its off position. Asuitable clock-spring Figs. 1 and 2, is provided for holding the switchdisk D in its off position when not in use.

From the above description the operation of my controlling mechanism, which is as follows, will be readily understood: The operating-sleeve C is actuated to turn the switchdisk D to its full on position, the current being applied gradually through the medium of the shunt N, and when the magnetic flux of the motor has reached a quantity which has been thought dangerous to the machine the cutout. magnet F is drawn inwardly by the solenoid H and the magnetic member G, thus releasing the pin Z from the shoulder j, en. abling the spring Z to pull theelement J forwardly until it' rests against the switch-disk D, carrying with it the knife-switch L, and thus breaking the current between the switchpoles L. By turning the switchdisk D to its ofi position the element J is carried back by the cam-face d of the switch-disk D and the pin Z engages with the shoulder j, thus by the aid of the spring Z holding the element J in its normal position when the switch-disk D is turned back to its full on position if the magnetic flux meanwhile has settled below the quantity which has been predetermined to be that at which the cutout magnet F should be actuated. When the drill is in use, the switch-disk D is prevented from turning under the tension of the spring d by means of a spring-clip (1 which is detachably hooked over a screw (1", secured to a lug (Z of the switch-disk D, as plainly shown in Fig. 2. When it is desired to revolve the switch-disk to its off position or to allow it to be thrown to said position by the spring at, the operating-sleeve C can be turned with suflicient force to overcome the tension of the spring-clip d, and thus release the switch-disk D therefrom, as will be clearly seen.

Although I have shown and described the automatic starting-switch and circuit-breaker comprising my motor-controller as particularly applied to drills, still I wish it understood that it can be used upon any electrically-driven tool or machine where it is desired to provide a small, compact, and efficient controlling mechanism.

Having described my invention in detail, that which I particularly point out and dis tinctly claim is 1. In motor-controllers, the combination with an electric motor; of a circuit for its armature connections; means for automatic ally breaking said circuit when the magnetic flux of the motor reaches a predetermined quantity; and a manually-operable switchdisk adapted, when it is actuated to its off position, to close the break in the circuit made by said automatically-operating means.

2. In motor-controllers, the combination with an electric motor; of a circuit for its armature connections; means for automatically breaking said circuit when the magnetic fluX of the motor reaches a predetermined quantity; a manually-operable switch-disk adapted, when it is actuated to its off position, to close the break in the circuit made by said automatically-opcrating means; and a short-circuiting switch included in said circuit and rendered operative during the actuation of said switch-disk to its on position.

3. In motor-controllers, the combination with an electric motor; of a circuit for its armature connections; a solenoid included in said circuit; circuitbreaking means adapted to be operated by the inward stroke of the core of said solenoid, such inward stroke of said core being efiected when the magnetic fluX of the motor reaches a predetermined quantity; a manually-operable switch-disk adapted, when it is actuated to its oil position, to close the break in the circuit made by said circuit-breaking means; and means for effecting the outward stroke of said core.

4. In motor-controllers, the combination with an electric motor; of a circuit for its armature connections; a solenoid included in said circuit; circuitbreaking means adapted to be operated by the inward stroke of the core of said solenoid, such inward stroke of said core being effected when the magnetic flux of the motor reaches a predetermined quantity; a manually-operable switch-disk adapted, when it is actuated to its ofl position, to close the break in the circuit made by said circuitbreaking means; means for effecting the outward stroke of said core; and a short-circuiting switch included in said circuit and rendered operative during the actuation of said switch-disk to its on position.

5. In motor controllers, the combination with an electric motor; of a circuit for its armature connections; means for automatically breaking said circuit when the magnetic fluX of the motor reaches a predetermined quantity; a rotatory short-circuiting switch included in said circuit; a series of fixed contact-clips supporting said switch; manuallyoperable switching means adapted, when they are actuated to their of position, to close the break in the circuit made by said automatically-operating means, the actuation of said manually-operable switching means effecting the rotation of said short-circuiting switch, the latter contacting with said clips during the actuation of the switching means to their on position, so as to render said short circuit operative.

6. In motor controllers, the combination with an electric motor; of a circuit forits armature connections; means for automatically breaking said circuit when the magnetic fluX of the motor reaches a predetermined quantity, including a solenoid, a core therefor, a pivoted lever connected at one end to said core, a lmife-switch, and switch-poles, said knifeswitch held to engagement with .the other end of said lever and held to contact with said switch-poles, when said core is in its outermost position; means for effecting the outward stroke of said core; and a manually-operable switch-disk adapted, when it is actuated to its off position, to close the break in the circuit made by said automatically-operating means.

7. In motor controllers, the combination with an electric motor; of a circuit for its armature connections; means for automatically breaking said circuit when the magnetic fluX of the motor reaches a predetermined quantity including a solenoid, a core there for, a pivoted lever connected at one end to said core, a knife-switch, and switch-poles, said knife-switch held to engagement with the other end of said lever and held to contact with saidsWitch-poles, when said core is in its outermost position; means for effecting the outward stroke of said core; a manuallyoperable switch-disk adapted, when it is actu ated to its off position, to close the break in the circuit made by said automaticallyoperating means; and a short circuiting switch included in said circuit and rendered operative during the actuation of said switchdisk to its on position.

8. In motor controllers, the combination with an electric motor; of a circuit for its armature connections; means for automatically breaking said circuit when the magnetic flux of the motor reaches a predetermined quantity, including a solenoid, an adjustable core therefor, a pivoted lever connected at one end to said core, a pivoted element held to engagement with the other end of said lever, when said core is in its outermost position, two switch-poles, and a knife-switch connected to said pivoted element and normally held by the latter to contact with said switch-poles; means for effecting the outward stroke of said core; and a manually-operable switch-disk adapted, when it is actuated to its off position, to close the break in the circuit made by said automaticallyoperating means.

9. In a portable electrically-operated drill, the combination of an electric motor provided with a suitable casing; a drill-spindle mounted in the latter; gearing connecting said motor and spindle; a manually-operable controller for said motor; and means for auto matically actuating said controller to assume the off position when the magnetic flux of the motor reaches a predetermined quantity.

Signed by me this 23d day of May, 1905.

ADOLPH PEDERSEN.

Attest:

JNo. F. OBERLIN, G. W. SAYWELL, 

